on July 13.
The vaccine is authorized for adults only. Should the Centers for Disease Control and Prevention follow suit and approve its use, Novavax would join Moderna, Pfizer and Johnson & Johnson on the U.S. market. A CDC panel of advisors is expected to consider the new entry on July 19.
The Novavax vaccine is only for those who have not yet been vaccinated at all.
“Today’s authorization offers adults in the United States who have not yet received a COVID-19 vaccine another option that meets the FDA’s rigorous standards for safety, effectiveness and manufacturing quality needed to support emergency use authorization,” FDA Commissioner Robert Califf, MD, said in a statement. “COVID-19 vaccines remain the best preventive measure against severe disease caused by COVID-19 and I encourage anyone who is eligible for, but has not yet received a COVID-19 vaccine, to consider doing so.”
The Novavax vaccine is protein-based, making it different than mRNA vaccines from Pfizer and Moderna. It contains harmless elements of actual coronavirus spike protein and an ingredient known as a adjuvant that enhances the patient’s immune response.
Clinical trials found the vaccine to be 90.4% effective in preventing mild, moderate or severe COVID-19. Only 17 patients out of 17,200 developed COVID-19 after receiving both doses.
The FDA said, however, that Novavax’s vaccine did show evidence of increased risk of myocarditis – inflammation of the heart – and pericarditis, inflammation of tissue surrounding the heart. In most people both disorders began within 10 days.
A version of this article first appeared on WebMD.com.